Fixed shaft rotary seal assembly

ABSTRACT

The disclosure herein relates to a rotary seal assembly, wherein a fixed shaft supports a rotary assembly, such as a cutter assembly for tunnel boring and mining, and the rotary assembly is mounted by antifriction bearings. In order to maintain lubricant in the bearing and exclude pieces of material being drilled from the bearings, a seal is provided. This seal is between a metallic ring carried by the rotor, as the outer bearing race of the antifriction bearing, and a graphite ring carried by the stator. The seal is between two relatively slidingly engaging, annular faces or annular seals. The graphite seal is urged toward the metallic ring so as to seat the graphite seal and the metallic ring.

1 1 Feb. 29, 1972 FIXED SHAFT ROTARY SEAL ASSEMBLY 3,469,85l 9Il969Enemark .308/187 Primary Examiner-Martin P. Schwadron AssistantExaminer-Frank Susko Attorney-Melvin A. Crosby S 7] ABSTRACT Thedisclosure herein relates to a rotary seal assembly, wherein a fixedshaft supports a rotary assembly, such as a cutter assembly for tunnelboring and mining, and the rotary assembly is mounted by antifrietionbearings. in order to maintain lubricant in the bearing and excludepieces of material being drilled from the bearings. a seal is provided.This seal is between a metallic ring carried by the rotor, as the outerbearing race of the antifriction bearing, and a graphite ring carried bythe stator. The seal is between two relatively slidingly engaging,annular faces or annular seals. The graphite seal is urged toward themetallic ring so as to seat the graphite seal and the metallic ring.

22 Claims, 13 Drawing Figures [72] Inventor: Douglas F. Winberg,Bellevue. Wash.

[73] Assignee: Subterranean Tools, Inc.

[22] Filed: May 8,1969

[2i] Appl.No.: 822,920

[52] U.S.CL ..308/l87.l [5i] lnt.Cl. ..Fl6c33/76 [58] FieldolSearch..308ll87,l87.l

[56] References Cited UNITED STATES PATENTS 2,3ll,287 2/1943 Boden..308ll87.l 2,077,881 4/1937 Gits ..308/187l 2,9ll,24l ll/l959 l-lorvathet al.. ...308/l87.l 3.2l6,5l3 ll/l965 Robbins et al. ..308/l87 r /7'-/g 3; 1 A

Patented Feb. 29, 1972 3,645,591

3 Sheets-Sheet 1 l llll IN VENTOR.

Patented Feb. 29, 1972 3,645,591

3 Sheets-Sheet 2 INVENTOR.

ATTORNE Patented Feb. 29, 1972 3,645,591

3 Sheets-Sheet f5 INVENLOR.

Dou la F wml q. BY

ATTORNEY FIXED SIIAI 'I ROTARY SEAL ASSEMBLY My invention relates to arotary seal assembly used in combination with a fixed shaft, a rotor,and an antifriction bearing means.

A typical environment in which my invention is used is illustrated anddescribed in US. Pat. No. 3,2l6,5l3, i sued Nov. 9, 1965, and of which Iam a coinventor.

Such prior art invention provides a metal-to-metal seal between tworings, one of which rings is carried by the stator and theother carriedby the rotor.

It is an object of my invention to improve the prior art metal-to-metalseal and to provide in place thereof a metal-tocarbon-graphite seal andbetween two rings, one carried by the rotor and the other carried by thestator.

It is a more specific object to provide a metal ring, carried by therotor, and which is preferably the outer race of an antifriction rollerbearing, and a carbon-graphite ring carried by the stator which includesthe fixed or nonrotating shaft.

Another more specific object is to provide a protective retainer shellorring for the graphite seal and to which is adhesively secured one faceof a rubber sheet ring, and to the other face of said rubber sheet ringis adhesively secured a carbongraphite ring.

Another more specific object is to employ in certain species. acompressed rubber O-ring to urge the upper portions of said brackets,and the carbon-graphite rings carried thereby, toward said protectiveretainer shell or ring and to employ compression springs to move thelower portions of said shell or ring, and the carbon-graphite ring,horizontally toward said metallic ring.

Another more specific object is to employ said shell or ring in a formwhich is substantially inverted L-shaped in section.

A further object is to provide a flexible O-ring to function as a staticseal or packing to retain the lubricant and exclude particles ofmaterial resulting from boring A still further object is to provide anO-ring to assist in radially locating and in supporting the graphiteseal within the sleeve.

An additional object is to provide an O-ring to provide a reaction meansto the turning moment on the graphite seal and which turning momentresults from friction at the seal face and rotation of the rotor sealface.

In connection with this invention, oneof the two rings used to providethe seal is a carbon-graphite ring. Such rings are readily available onthe market and one source thereof is from Pure carbon Company, Inc., ofSt. Marys, Pennsylvania. The products are sold under the trade name ofPUREBON. While many grades of carbon-graphite are manufactured by saidcompany and many of the same may be satisfactorily used in practicing ofmy invention, a typical one has the following specification as listed bysaid company:

GRADEP55; Apparent Density (gm.lcc.)2.3$; HardnessShore Scleroscope-90;Compress. psi-42,500; Transverse p.s.i.- l 3,000; Tensile p.s.i.-9,000', Modulus of Elasticity x l4.0; Neutral Atmosphere F.)- 1,500;Oxidizing Atmosphere F.)-SOO; Corrosion Resistance GroupRl0; Coefficientof Thermal Expansion (in./in./ F. X l0)3.0; Permeability (Darcies IO)Porosity (Vol. percent)5.

Another typical one has the following specification as listed by saidcompany:

GRADE P-658RC; Apparent Density (grn./cc.) l .80 Hardness-ShoreScleroscope-90; Compress. p.s.i. 37,500; Transverse psi-11,000; Tensilep.s.i.8,000; Modulus of Elasticity X l0-3.l Neutral AtmosphereF.)-l,200; Oxidizing Atmosphere F.)500; Corro sion Resistance Group-R3;Coefi'rcient of Thermal Expansion (in./in./ F. X l0")2.2; Permeability(Darcies l0')-0.3', Porosity (Vol. percent)-2.

Some of the main advantages in the use of carbon-graphiteto-metal sealare: self-lubrication from the carbon-graphite particles; reasonablyhigh compression strength; resistance to chemical corrosion; resistanceto oxidation; low coefficient of friction; and wear resistance.

The above-mentioned objects and advantages of this invention, togetherwith other inherent in the same. will become explicit or implicit as thedescription of this invention continues in connection with the drawings,throughout which like reference numerals indicates like parts andwherein:

FIG. I is a view partly in section and partly in elevation, of acutterhead incorporating the sealing means of this invention;

FIGS. 2 and 3 are enlarged fragmentary views of parts shown in FIG. 1and more particularly the parts providing the seal of this invention;

FIGS. 4 and 5 are enlarged fragmentary sectional views takenrespectively, substantially on broken lines 4-4 and 5- 5 of FIG. 1;

FIG. 6 is a fragmentary lateral cross-sectional view of another sleevehaving an inner cylindrical or an inner radial surface and of a sealhaving an outer, cylindrical or an outer radial surface with an O-ringbetween them;

FIG. 7 is a lateral, cross-sectional view of a sleeve having an innercylindrical or an inner radial surface and a seal having an outercylindrical or an outer radial surface with an O-ring between them;

FIG. 8 is a fragmentary lateral cross-sectional view of a sleeve havingan angular or conical inner surface and a seal having a cylindrical orradial outer surface with an O-ring between them;

FIG. 9 is a fragmentary lateral cross-sectional view illustrating asleeve having an inner cylindrical or an inner radial surface and a sealhaving an angular or conical outer surface and an O-ring between them;

FIG. I0 is the same as FIG. 2 and illustrates a sleeve having an angularor conical inner surface and a seal having an angular or conical outersurface and an Oring between them; and

FIG. 11 is a fragmentary lateral cross sectional view of another sleevehaving an inner cylindrical or an inner radial surface and of a sealhaving an outer cylindrical or an outer radial surface with an O-ringbetween them and a spring directly urging the seal against the race of abearing; and,

FIG. I2 is a fragmentary lateral cross-sectional view of another sleevehaving an outer cylindrical or an inner radial surface and of a seathaving an outer cylindrical or an out radial surface with an O-ringbetween them and a spring bearing against a protective shell for theseal.

The cutter assembly of FIG. I is especially adapted for use on thecutterhead of a tunnel boring machine, such as the type described in theapplications, wherein I am one of the coinventors, and whichapplications bear Ser. No. 203,846, filed June 20, 1962, and Ser. No.335,882, filed Jan. 6, 1964 (now US. Pat. No. 3,216,5l3). For a moreextensive and comprehensive discussion and disclosure of a tunnel boringmachine, reference is made to such applications. To the extent that itmay be necessary or expedient for a clear understanding of the presentinvention, such applications are hereby expressly incorporated herein byreference.

Referring now to the drawings, a fixed or nonrotating shaft I0rotatively mounts a cutting wheel I2. In view of the expected wear onthe cutting portion of the cutting wheel 12, the same or the cuttingportion thereof should be replaceable, all as is taught by saidapplication, now US. Pat. No. 3 ,2l6,5 l 3.

Encircling the shaft 10 and the midlength thereof are two inner bearingraces 14 and I6 which are relatively fixed on said shaft I0 duringoperation. The inner bearing races 14 and I6 are spaced from each otheraxially on shaft I0, as by cutter I2, and provide a chamber IS. Theinner races I4 and I6 mount roller bearings 20 and 22 and in turn theouter races 24 and 26. For points of reference, the terms inner andouter" as used herein define proximity to the longitudinal axis of theshaft 10 while "inside" and "outside define proximity to a transverseplane passing through the midlength of the shaft I0. The outer races 24and 26 are carried by and spaced from each other on shaft I0 by thecutting wheel I2.

Sleeves 28 and 30 are spaced apart in a direction axially of shaft I0and retain inner races l4 and I6 from movement toward the outside. Thesleeves 28 and 30 are retained against movement toward the outside byend caps 32 and 34. One of the end caps 32 or 34 may be rigid with thefixed shaft and the other thereof may be screwed thereto as by screw 37.

Thus far in connection with the description of the drawings, there hasbeen described substantially the structure of said US Pat. No. 3,216,5l3or the equivalent thereof. However, a different seal is provided in thisinvention to seal in the lubricant for the roller bearings and 22 and toseal out the grit and residue resulting from the grinding and cuttingaction of the cutting wheel I2. This seal comprises a metallic ringcarried by the rotor, comprising the cutting wheel 12, and which ringmay be in the form of the outer races 24 and 26. The sealing faces ofsaid rings will be the annular ring faces 36 and 38 (FIGS. 2 and 3).Sealing against said faces 36 and 38 are stationary annular faces 40 and42 of carbon-graphite rings 44 and 46. Each of said rings 44 and 46 ispreferably mounted by adhering the same to an annular ring of ayieldable, flexible material 48, said yieldable, flexible material 48may be rubber or a plastic such as polyurethane. 48 in turn may bebonded to a hard, protective shell 50 of metal or one of the modernplastics. In addition, the resilient connection between thecarhon-graphite rings 44 and 46 through the yieldable, flexible material48 to the bracket 50 is desirable. Preferably, the inner walls 52 and 54of each sleeve 28 and 30, adjacent respectively the outside and outersurfaces of the carbon-graphite rings 44 and 46, form substantially aright angle with the surface 54 being angular and thus the angle of saidopening is an obtuse angle. The protective shell 50 conforms to theconfigurations of the juncture of the walls 52 and 54 and issubstantially of inverted L-shape and has a portion 66 inclinedoutwardly to the horizontal and a portion 68 disposed substantiallyvertically. A flexible yieldable O-ring 55 is disposed between a wall 54and the adjacent portion 66 of a bracket 50. When in use said O-ring 55is compressed, as shown, and thus provides a force diagonally directedagainst a carbon-graphite ring 44 inwardly and to the inside and towardthe metal ring provided by an outer race 24 of an antifriction bearing.A compression spring 57 is mounted within a recess 58in sleeve 28 andprovides a horizontal pressure between a sleeve 28 and a portion 68 ofthe bracket 50. By so urging bracket portions 68 a horizontal pressureis exerted urging the carbon-graphite ring 44 to the inside.

The free inner edge of 68 is serrated to have recesses 70 and tongues 72(FIG. 4). The sleeve 28 is provided with a plurality ofcircumferentially spaced tongues 74 and recesses 76. The tongues 72 fitwith the recesses 76 and the tongues 74 fit with the recesses 70 topermit relative axial movement of the sleeve 28 and the protective shell50. Likewise these tongues and recesses can function to restrictrelative axial movement of the sleeve and shell.

The graphite ring 46 has adhered to its outside surface and edge ayieldable, flexible material 80. The yieldable, flexible material 80 maybe rubber or a plastic such as polyurethane or other suitable material.There is adhered to the outside of 80 a protective shell 82 and whichshell 82 may be generally of a ringlike configuration. The protectiveshell 82 on its outer part has a sloping surface 84 which covers theouter sloping surface of the graphite ring 46. Then, the sloping region84 is directed inwardly into an annular region 86. The outer part of thean nular region 86 covers the inner part of the yieldable, flexible ring80. Then, the innermost part of 82 bends inwardly at 88 to fonn astiffener for 82. Numeral 88 makes a more stiff pro tective shell 82. Inthe sleeve 30 there are a number of recesses 90. In the recesses 90there are a number of spring 92 or yieldable members 92. The springs 92press against the sleeve 30 and also against the annular region 86 ofthe protective shell 82.

An O-ring 56 is positioned between the surface 54 of the sleeve 30 andbetween the surface 84 or the region 84 of the protective shell 82. TheO-ring 56 urges the graphite seal 46 toward the surface 38 of the race26. Further. the spring 92 urges the graphite seal 46 toward the surface38 of the race 26.

The O-rings 55 and 56 are of a yieldable, flexible material andsufficiently resilient to urge the graphite seals toward the face of therace. Suitable materials of construction for the 0- rings 55 and 56 arerubber and plastic such as polyurethane and other plastics.

In FIG. 3 there is illustrated the use of a pin 87. The pin 87 projectsthrough the shell 86 and into the recess 90. The pin 87 restricts therotation of the hard protective shell 82 and the graphite seal 46. Bythis restriction of rotation there is less stress and strain on theO-ring 56 and, therefore, the O-ring 56 has a longer life.

The use of a graphite-to-metal seal is of value in regard to therestricted space application in certain instances. In certain cuttersand other mechanical devices, there is a limited space to provide aseal. Instead of two metal-to-metal seals or instead of twographite-to-graphite seals there may be used a single graphite seal inconjunction with the member of either a stationary or metal surface or arotating metal surface. Further, the rotor I2, of this invention, is notresiliently mounted and therefore the use of the rubber O-ring and thegraphite seal assist in decreasing the wear on the sealing surfaces. Anadvantage of a graphite seal is that for small production runs it isposible to machine the graphite to the desired configuration. This isnot economically possible with a metal seal. Further, with a graphiteseal against a metal surface, the metal surface need not be finished tosuch a high degree as a metal-tometal surface. Graphite is softer thanmetal and therefore will wear to seat itself with the metal sealingsurface. Most of the metal sealing surfaces are a stainless steel or asteel. If there be a metal-to-metal seal, it is necessary to have a fineand accurate finish on each of the metal sealing surfaces. With agraphiteto-metal seal, the surface of the metal need not be machined tosuch a fine and high quality finish as the graphite will readily wearand seat itself with the metal seal.

In these seals, the O-ring assists in preventing dirt, extraneousmaterial and rock from entering into the bearing area. Further, theO-ring assists in locating the seal assembly and radially provides aconcentric mounted seal base with respect to the metal seal. Inaddition, the O-ring proves a reaction means to the turning moment onthe graphite seal and which turning moment results from friction at theseal face and rotation of the seal face of the rotor. Finally, theO-ring provides a resilient mounting for the graphite seal assemblythereby tending to permit the seal assembly to vibrate with a relativefrequency of the mating metal seal face on the rotor and without unduewear on the seal face of the graphite. There may be introduced into theinterior of the cutter an oil lubricant to assist in lubricating thebearings. However, the lubricant also functions as a heat transfer fluidto conduct heat away from the graphite-to-metal surfaces and into thebody of the oil fluid and from there conduct heat to the metal shell orthe rotor and the sleeve. This conduction of heat away from the sealslessens the possibility of a high temperature rise in the vicinity ofthe seals and a high temperature rise in the O ring. Therefore, there ISless possibility of damage to the O- ring. If the temperature becomestoo high in the O-ring, there may be a permanent deformation andtherefore the O-ring looses its urging force to urge the seal againstthe metal surface of the bearing. In this regard, the springs 57 and 92assist in urging the seals 44 and 46 against the sealing face or themetal surface of the bearing. The springs 57 and 92, being of metal,will not readily loose their spring coefficient with a moderate rise intemperature in the vicinity of the seals.

The seal retainer shells S0 and 82 are of value in making it possible tomold a graphite seal in the form of a ring. The molded graphite seal inthe form of the ring will not have as line a tolerant as the machinegraphite seal. However, by providing a yieldable, flexible material suchas 48 or between the graphite seals and the protective shell, the varia--tion in tolerance can be compensated. Then, with the protective metalit is possible to have a close tolerance with the protective metalshell. In this regard, a lower cost and satisfactory seal can be formed.

From the foregoing it will now be apparent that I provided incombination with a fixed shaft, as shaft 10, a rotor typified by acutting wheel 12 and antifriction bearing means, as roller bearings 20or 22, and a rotary seal assembly. This rotary seal assembly comprises ametallic ring carried by the rotor, preferably an outer race 24 or 26 ofthe roller bearings, and which ring provides a rotating sealing face 36or 38. In sliding, contacting relation with said sealing face 36 or 38is a sealing face 40 or 42 of a carbon-graphite ring 44 or 46. The meansto move said carbon-graphite face toward and maintain the same insealing relation with a metallic sealing face 36 or 38 comprises elasticrubber O-rings S5 and compression springs 57. The said O-rings S5 andcompressing springs 57 function through brackets 50, which aresubstantially of inverted L- shape, to provide a diagonally directedpressure and a horizontally directed pressure against carbon-graphiterings 44 and 46. The brackets 50 mount said carbon-graphite rings 44 and46 through the intermediary of an elastic rubber sheet ring 48 havingone face thereof adhered to said carbon-graphite rings and the otherface thereof adhered to said brackets 50.

FIGS. 2 and illustrate on form of a sleeve 28 and a ring or seal 44 ofgraphite. As is seen in FIG. 10 the inner surface of the sleeve 28 hasan angular or conical wall 54 and an annular wall 100. In the annularwall 100 is a recess or cavity 58 having a spring 57 positioned therein.

The seal 44 has a stationary annular face 40 and a sloping angular orconical outer face 102.

The wall 54 and the conical face 102 slope in substantially the samedirection and are substantially parallel. The ring 44 has an annularface 104 and which face is substantially parallel to the annular face 40and also substantially parallel to the annular wall 100. There isattached to the conical face 102 and annular face 104 the soft flexibleyieldable material 48. There is positioned over the soft flexibleyieldable material 48 a hard protective shell 50. The hard protectiveshell 50 has a sloping region substantially parallel to the conical face102 and to the wall 54 and has a straight region 68 substantiallyparallel to the annular wall 100.

The spring 57 is positioned in the cavity in recess 58 and pushesagainst the portion 68 of the hard protective shell 50. Also, there ispositioned between the portion 66 of the hard protective shell 50 andthe wall 54 an O-ring 55. The O-ring 55 functions as a sealing agent andalso, because of the sloping wall 54 and the conical face 102, functionsto push the ring 44 and stationary annular face 40 of said ring againstthe annular face 36 of the outer bearing race 24.

Again, the annular ring 44 is of graphite.

in FIG. 6 there is illustrated a fragmentary portion 110 of a rollingcutter having a sleeve 112. The sleeve 112 has an inner cylindrical orradial surface 114 and an annular surface 116. ln the wall of the sleevethere is a recess or cavity 118 and a spring 120 is positioned in saidrecess or cavity.

In the rolling cutter 110 there is a rotating or revolving outer bearingrace 122. Also, there is a ring 124 of graphite having an annularsealing surface 126 which seals against annular surface 128 against thesurface of the outer bearing race 122.

The ring 124 has an outer flat cylindrical or radial surface 130 and anannular surface 132. The annular surface 132 is substantially parallelto the annular sealing surface 126 and also substantially parallel tothe wall 116. There is positioned on the surface 132 a hard, protectivemetal or shell 134 and which shell extends in the form of a ring or atorus on the inner surface of 132 and inwardly of the inner cylindricalradial surface 114. The spring 120 pushes against the inner end of thehard protective shell 134 so as to push the ring 124 and the sealingsurface 126 of said ring against the sealing surface 128 of the outerrace 122.

There is an O-ring 136 positioned between the inner cylindrical surface114 and the outer cylindrical surface 130. This O-ring functions as asealing agent and does not function to force the sealing surface 126against the sealing surface 128.

In fact, any force exerted by the O-ring 136 to force the sealingsurface 126 against the sealing surface 128 is an incidental force.

In FIG. 7 there is illustrated substantially the same structure as inFIG. 6 except that there is positioned between the hard protective shell134 and the ring 124 a flexible yieldable material 138. This flexibleyieldable material 138 takes up shock and vibrations in the rollingcutter. The ring 124 may be of metal or of graphite. The O-ring 136 maybe of rubber or a suitable plastic such as polyurethane. The hardprotective shell 134 may be of metal such as a steel ring. The flexibleyieldable material 138 may be of rubber or of plastic such aspolyurethane or another suitable plastic.

In FIG. 8 there is illustrated a rolling cutter having a sleeve 152. Theinner surface of said sleeve 152 is an angular or conical inner surface154. The sleeve has an annular side wall 156. In the sleeve 152 there isa cavity or recess 158 and in the cavity or recess 158 there is a spring160.

The rolling cutter 150 has an outer race 162 with an annular sealingsurface 164. Also, the cutter 150 has a ring of graphite with an annularsealing surface 168 which bears against the annular sealing surface 164of the race 162. The ring 166 has an outer cylindrical or radial surface170 and an outer annular surface 172. The annular surface 172 issubstantially parallel to the sealing surface 168 and also issubstantially parallel to the wall 156.

There is attached to the surface 172 of the ring 166 a circular metalplate 176. The spring 160 bears against the inner surface of the plate176 so as to push the ring 166 and the sealing surface 168 against thesealing surface 164.

There is positioned an O-ring 178 benveen the inner angular or conicalsurface 154 and the outer cylindrical or radial sur face 170. The O-ring178 functions primarily as a sealing agent to keep dirt and extraneousmatter out of the bearings in the interior of the rolling cutter. Anyforce exerted by the O- ring 178 to force the ring 166 against the outerrace 162 and the annular face 168 against the annular face 164 is onlyincidental. This forcing of the face 168 against the face 164 isachieved by means of a spring 160.

In FIG. 9 there is illustrated a fragmentary portion of a rolling cutter180 having a sleeve 182 and an inner cylindrical or radial surface 184.The sleeve 182 has an annular wall 186. In the annular wall 186 there isa cavity or recess 188. In the cavity 188 there is a spring 190.

The rolling cutter 180 has an outer bearing race 192 with an annularsurface 194.

in the rolling cutter 180 there is also a ring 196 of graphite. Saidring 196 has an annular surface 198 for sealing with the surface 194.Further, the ring 196 has an outer radial or cylin drical surface 200and a sloping conical or angular surface 202. Further, the ring 196 hasan outer annular surface 204. On the annular surface 204 there ispositioned a ring of a flexi ble yieldable material 206 and a hardprotective shell or ring 208. The ring 208 extends inwardly of the ring196. The spring 190 bears against the inner end of the ring 208 so as topush the ring 196 against the race 192 and to push the sealing sur face198 against the sealing surface 194.

There is positioned between the outer sloping or conical surface 202 andthe inner cylindrical or radial surface 184 an O-ring 210. Said O-ringbears against the sloping surface 202 so as to force the ring 196against the race 192 and to force the surface 198 against the surface194. in addition. the O-ring 210 functions as a sealing agent forsealing the interior of the rolling cutter 180 against the entrance ofextraneous dirt, rock and the like.

In the cutter 180 the ring 196 is forced against the ring 192 and thesurface 198 is forced against the surface 194 by a combination of thespring 190 pushing against the hard protective ring 208 and by theO-ring 210 pushing against the sloping surface 202.

In FIG. 11 there is illustrated a fragmentary portion of a rollingcutter 220 having a sleeve 222 and an inner cylindrical or radialsurface 224. The sleeve 222 has an annular wall 226.

In the annular wall 226 there is a cavity or recess 228. In the cavity228 there is a spring 230.

The rolling cutter 220 has an outer bearing race 232 with an annularsurface 234.

In the rolling cutter 220 there is also a ring 236. Said ring has anannular surface 238 for sealing with the surface 234. Further, the ring236 has an outer radial or cylindrical surface 240. Further, the ring236 has an outer annular surface 242. ln FIG. 11 it is seen that thecavity or recess 228 is aligned with the ring 236. Also, the spring 230bears directly against the annular surface 242 of the ring 236 so as toforce the annular sealing surface 238 of the ring against the annularsealing surface 234 of the bearing race 232.

There is positioned between the outer radial surface 240 of the ring 236and the inner cylindrical or radial surface 224 an O-ring 246. TheO-ring 246 functions as the seal and any urging of the O-ring 246 on thering 236 so as to force the seal 236 against the bearing race 232 is ofincidental importance. The primary function of the O-ring 246 is tofunction as a seal.

In FIG. 12 there is illustrated a fragmentary portion of a rollingcutter 250 having a sleeve 252 and an inner cylindrical or radialsurface 254 but with the tip conically sloping at 256. The sleeve 252has an annular wall 258. In the annular wall 258 there is a cavity orrecess 260. In the cavity or recess 260 there is a spring 262.

The rolling cutter 250 has an outer bean'ng race 264 with an annularsurface 266.

In the rolling cutter 250 there is a ring 268. Said ring 268 has anannular surface 270 for sealing with the annular surface 266. Further,the ring 268 has an outer flat radial or cylindrical surface 272. Inaddition, the ring 268 has an outer radial or cylindrical surface 272.In addition, the ring 268 has an outer annular surface 274. On theannular surface 274 there is positioned a ring of a flexible yieldablematerial 276. The ring 276 is of slightly larger external diameter thanthe ring 268 so that the ring 276 projects outwardly farther or beyondthe external diameter of the ring 268. Also, there is positioned on theoutside of the ring 276 a ring 278 having a larger external diameterthan the ring 268 and a smaller internal diameter than the ring 268 sothat the ring 276 projects farther outwardly than the ring 268 and alsoprojects farther inwardly than the ring 268. The ring 276 may be adheredto the ring 268 and also to the ring 278. In FIG. 12 it is seen that thespring 262 urges against the hard protective shell 278 so as to urge thering 268 and the annular sealing surface 270 against the annular sealingsurface 266 on the bearing race 264.

There is positioned between the outer radial or cylindrical surface 272to the ring 268 and the inner radial or cylindrical surface 254 to thesleeve 252 an O-ring 280. The primary function of the O-ring 280 is thatof a seal. The primary function of the spring 262 is to force the ring268 against the bearing race 264. Any forcing of the ring 268 againstthe bearing race 264 by the O-ring 280 is incidental. Also, it is seenthat with the projection of the ring 276 and the projection of the ring278 outwardly and beyond the outer radial surface 272 of the ring 268that there is an effective barrier for preventing the O-ring 280 workingover and beyond the annular surface 274 and the ring 276 and thereby notfunction as a seal.

FIG. 13 is a fragmentary lateral cross-sectional view of another sleevehaving an inner recessed partially circular seat for receiving andseating a bull ring and an outer cylindrical or an outer radial surfacewith said O-ring between them and a spring bearing against the graphitering.

In FIG. 13 there is illustrated a fragmentary portion of a rollingcutter 300 having a rotor 302 and a sleeve 304. The sleeve 304 has aninner recessed partially circular seat 306 and an outer cylindrical lip308. Also, the sleeve 300 has an annular wall 310 and a recess 312 inthe wall 310. The rotor comprises a bearing race 314. There is agraphite ring 316 having an annular sealing surface 318. The race 314has an annular sealing surface 320. The surfaces 318 and 320 are incontact with each other and seat with each other. The ring 316 has anouter cylindrical or an outer radial surface 321. There is positionedbetween the outer cylindrical surface 321 and the inner recessedpartially circular seat 306 a sealing means or an O-ring 322. It is seenthat the O-ring 322 in the inner recessed partially circular seat 306does not force the sealing surface 318 of the graphite ring 316 againstthe sealing surface 320 of the bearing race 314. The spring 324 in therecess 312 forces the graphite ring 316 against the bearing race 314 sothat the annular surface 318 bears against and seats with the annularsurface 320 of the bearing race 314.

In FIG. 13 and sleeve 300, I have provided an inner recessed partiallycircular seat for receiving and seating an O-ring and which O-ring doesnot force the graphite ring against the hearing race. Further, the Oring322 is in this circular seat 306 and is positioned there so that it ispossible to assemble the sleeve structure, the sealing means, and thegraphite ring 316. With the use of such a circular seat 306, it ispossible to use the graphite ring 316 having an outer cylindricalsurface 321. As a result, the cost of manufacture of the graphite ring316 is considerably reduced and therefore the cost of the seals and therolling cutter are reduced.

The hard protective rings 68, 86, 278, 134, 176, and 208 may be of metalsuch as steel. The rings 44, 46, 124,268, 236, 166, 196, and 316 may beof graphite.

The yieldable flexible material 48, 80, 138, 206, and 276 may be ofrubber or a plastic, such as polyurethane.

The O-rings 55, S6, 136, 178, 210, 246, 280, and 322 may be of rubber ora suitable plastic, such as polyurethane.

As previously stated the graphite-to-metal seal need not be run in,prior to actual use, as is necessary with metal-to-metal seals. This isa saving in time and money.

Obviously, changes may be made in the forms, dimensions and arrangementsof the pans of my invention without departing from the principlethereof, the above setting forth only a preferred form of embodiment ofmy invention.

Having presented my invention, what I claim is:

1. A sealing means comprising in combination:

a. a fixed shaft assembly;

b. a rotor;

c. an antifriction bearing means mounting said rotor on said fixed shaftassembly ring of a rotary seal assembly;

d. said seal assembly comprising a radial metallic ring on the race ofsaid antifriction bearing means and which radial metallic ring serves asa radial sealing face;

e. a graphite ring carried by said fixed shaft assembly and having aradial sealing face disposed in sliding contacting relation with saidradial sealing face of said metallic ring;

f. a first means resiliently urging said metallic ring and said graphitering toward each other;

g. said assembly having a sleeve;

h. said sleeve having an inner conical surface;

i. said graphite ring having an outer cylindrical surface; and,

j. a second sealing means positioned between said inner conical surfaceand said outer cylindrical surface.

2. A sealing means according to claim 1 and comprising:

a. said second sealing means being an O-ring.

3. A sealing means according to claim 1 and comprising:

a. said first means comprising a spring positioned between said sleeveand said graphite ring; and,

b. said spring urging said graphite ring toward said race.

4. A sealing means according to claim 1 and comprising:

a. a plate connecting with said graphite ring and on mat face of diering facing said sleeve;

1:. said first means comprising a spring positioned between said sleeveand said plate; and,

c. said spring urging said graphite ring toward said race.

5. A sealing means according to claim 4 and comprising:

a. said second sealing means being an O-ring.

6. A sealing means comprising in combination:

a. a fixed shaft assembly;

b. a rotor;

c. an antifriction bearing means mounting said rotor on said fixed shaftassembly of a rotary seal assembly;

d. said seal assembly comprising a radial metallic ring on the race ofsaid antifriction bearing means and which radial metallic ring serves asa radial sealing face;

e. a graphite ring carried by said fixed shaft assembly and having aradial sealing face disposed in sliding contacting relation with saidradial sealing face of said metallic ring;

f. a first means resiliently urging said metallic ring and said graphitering toward each other;

g. said assembly having a sleeve;

h. said sleeve having an inner cylindrical surface;

i. said graphite ring having an outer sloping surface; and,

j. a second sealing means positioned between said inner cylindricalsurface and said outer sloping surface.

7. A sealing means according to claim 6 and comprising:

a. said second sealing means being an O-ring.

8. A sealing means according to claim 6 and comprising:

a. said first means comprising a spring positioned between said sleeveand said graphite ring; and,

b. said spring urging said graphite ring toward said race.

9. A sealing means according to claim 6 and comprising:

a. a plate connecting with said graphite ring and on that face of thering facing said sleeve;

b said first means comprising a spring positioned between said sleeveand said plate; and,

c. said spring urging said graphite ring toward said race.

10. A sealing means according to claim 9 and comprising:

a. said second sealing means being an O-ring.

11. A sealing means comprising in combination: a fixed shaft assembly, arotor, an antifriction bearing means mounting said rotor on said fixedshaft assembly, and a rotary sea] assembly, said seal assemblycomprising a radial metallic ring on a race of said antifriction bearingmeans and which radial metallic ring serves as a radial sealing face, agraphite ring car ried by said fixed shaft assembly and having a radialsealing face disposed in sliding contacting relation with said radialsealing face of said metallic ring, and a first means resiliently urgingsaid metallic ring and said graphite ring toward each other and sealingsaid graphite ring to said fixed shaft assembly and including aresilient O-ring positioned between said graphite ring and said fixedshaft assembly.

12. A sealing means according to claim 11 in which said first means alsoincludes spring means between said graphite ring and said fixed shaftassembly.

13. A sealing means according to claim 11 in which said radial metallicring is part of the said bearing race of said an tifriction bearingmeans.

14. A sealing means according to claim ll in which said gra phite ringhas a sloping surface facing away from said metallic ring, said fixedshaft assembly having a sloping surface radially spaced from the saidsloping surface on said graphite ring, said O-ring being positionedbetween said sloping surfaces and urging graphite seal toward saidmetallic ring while sealing between said sloping surfaces.

15. A sealing means according to claim 11 which includes a protectiveretainer shell ring on the graphite seal on the side thereof facing awayfrom said metallic ring, said protective retainer shell ring having agenerally radial part and an annular part, said resilient O-ring beingpositioned between said radial part of the protective retainer shellring and an adjacent part of the fixed shaft assembly, and spring meanspositioned between said annular part of the protective retainer shellring and an adjacent part of the fixed shaft assembly.

16. A sealing means according to claim ll which includes a sleeveforming a part of said fixed shaft assembly and disposed on the oppositeside of said graphite ring from said metallic ring, said sleeve havingan inner conical surface adjacent said graphite ring, said graphite ringhaving an outer sloping surface substantially parallel to said conicalsurface and spaced therefrom, and said resilient O-ring being positionedbetween and sealingly engaging said inner conical surface and said outersloping surface.

17. A sealing means according to claim 11 which includes a sleeveforming a part of said fixed shaft assembly and disposed on the oppositeside of said graphite ring from said metallic ring, said sleeve havingan inner cylindrical surface adjacent said graphite ring, said graphitering having an outer cylindrical surface, and said resilient O-ringbeing positioned between and sealingly engaging said inner cylindricalsurface and said outer cylindrical surface.

18. A sealing means according to claim 11 which includes a sleeveforming a part of said fixed shaft assembly and dispose on the oppositeside of said graphite ring from said metallic ring, said sleeve havingan inner conical surface adjacent said graphite ring, said graphite ringhaving an outer cylindrical surface, and said resilient O-ring beingpositioned between and sealingly engaging said inner conical surface andsaid outer cylindrical surface.

19. A sealing means according to claim 11 which includes a sleeveforming a part of said fixed shaft assembly and disposed on the oppositeside of said graphite ring from said metallic ring, said sleeve havingan inner cylindrical surface adjacent said graphite ring, said graphitering having an outer sloping surface radially spaced from saidcylindrical surface, and said resilient O-ring being positioned betweenand sealingly engaging said inner cylindrical surface and said outersloping surface.

20. A sealing means according to claim 11 which includes a protectiveretainer shell ring on the graphite ring, and positioning means engagingsaid shell ring and said fixed shaft assembly and operable forrestricting rotation of said protective retainer shell ring and saidgraphite ring with respect to said fixed shaft assembly.

21. A sealing means according to claim 20 in which said fixed shaftassembly comprises a recess and said positioning means includes a pinconnecting said recess and said protective retainer shell ring torestrict rotation of said protective retainer shell ring and saidgraphite ring with respect to said fixed shaft assembly.

22. A sealing means according to claim H in which said fixed shaftassembly includes a sleeve on the opposite side of said graphite ringfrom said metallic ring, said sleeve having an inner recessed partiallycircular seat, said graphite ring having an outer cylindrical surface,and said resilient O'ring being positioned between and sealinglyengaging said inner recessed partially circular seat and said outercylindrical surface.

1. A sealing means comprising in combination: a. a fixed shaft assembly;b. a rotor; c. an antifriction bearing means mounting said rotor on saidfixed shaft assembly ring of a rotary seal assembly; d. said sealassembly comprising a radial metallic ring on the race of saidantifriction bearing means and which radial metallic ring serves as aradial sealing face; e. a graphite ring carried by said fixed shaftassembly and having a radial sealing face disposed in sliding contactingrelation with said radial sealing face of said metallic ring; f. a firstmeans resiliently urging said metallic ring and said graphite ringtoward each other; g. said assembly having a sleeve; h. said sleevehaving an inner conical surface; i. said graphite ring having an outercylindrical surface; and, j. a second sealing means positioned betweensaid inner conical surface and said outer cylindrical surface.
 2. Asealing means according to claim 1 and comprising: a. said secondsealing means being an O-ring.
 3. A sealing means according to claim 1and comprising: a. said first means comprising a spring positionedbetween said sleeve and said graphite ring; and, b. said spring urgingsaid graphite ring toward said race.
 4. A sealing means according toclaim 1 and comprising: a. a plate connecting with said graphite ringand on that face of the ring facing said sleeve; b. said first meanscomprising a spring positioned between said sleeve and said plate; and,c. said spring urging said graphite ring toward said race.
 5. A sealingmeans according to claim 4 and comprising: a. said second sealing meansbeing an O-ring.
 6. A sealing means comprising in combination: a. afixed shaft assembly; b. a rotor; c. an antifriction bearing meansmounting said rotor on said fixed shaft assembly of a rotary sealassembly; d. said seal assembly comprising a radial metallic ring on therace of said antifriction bearing means and which radial metallic ringserves as a radial sealing face; e. a graphite ring carried bY saidfixed shaft assembly and having a radial sealing face disposed insliding contacting relation with said radial sealing face of saidmetallic ring; f. a first means resiliently urging said metallic ringand said graphite ring toward each other; g. said assembly having asleeve; h. said sleeve having an inner cylindrical surface; i. saidgraphite ring having an outer sloping surface; and, j. a second sealingmeans positioned between said inner cylindrical surface and said outersloping surface.
 7. A sealing means according to claim 6 and comprising:a. said second sealing means being an O-ring.
 8. A sealing meansaccording to claim 6 and comprising: a. said first means comprising aspring positioned between said sleeve and said graphite ring; and, b.said spring urging said graphite ring toward said race.
 9. A sealingmeans according to claim 6 and comprising: a. a plate connecting withsaid graphite ring and on that face of the ring facing said sleeve; b.said first means comprising a spring positioned between said sleeve andsaid plate; and, c. said spring urging said graphite ring toward saidrace.
 10. A sealing means according to claim 9 and comprising: a. saidsecond sealing means being an O-ring.
 11. A sealing means comprising incombination: a fixed shaft assembly, a rotor, an antifriction bearingmeans mounting said rotor on said fixed shaft assembly, and a rotaryseal assembly, said seal assembly comprising a radial metallic ring on arace of said antifriction bearing means and which radial metallic ringserves as a radial sealing face, a graphite ring carried by said fixedshaft assembly and having a radial sealing face disposed in slidingcontacting relation with said radial sealing face of said metallic ring,and a first means resiliently urging said metallic ring and saidgraphite ring toward each other and sealing said graphite ring to saidfixed shaft assembly and including a resilient O-ring positioned betweensaid graphite ring and said fixed shaft assembly.
 12. A sealing meansaccording to claim 11 in which said first means also includes springmeans between said graphite ring and said fixed shaft assembly.
 13. Asealing means according to claim 11 in which said radial metallic ringis part of the said bearing race of said antifriction bearing means. 14.A sealing means according to claim 11 in which said graphite ring has asloping surface facing away from said metallic ring, said fixed shaftassembly having a sloping surface radially spaced from the said slopingsurface on said graphite ring, said O-ring being positioned between saidsloping surfaces and urging graphite seal toward said metallic ringwhile sealing between said sloping surfaces.
 15. A sealing meansaccording to claim 11 which includes a protective retainer shell ring onthe graphite seal on the side thereof facing away from said metallicring, said protective retainer shell ring having a generally radial partand an annular part, said resilient O-ring being positioned between saidradial part of the protective retainer shell ring and an adjacent partof the fixed shaft assembly, and spring means positioned between saidannular part of the protective retainer shell ring and an adjacent partof the fixed shaft assembly.
 16. A sealing means according to claim 11which includes a sleeve forming a part of said fixed shaft assembly anddisposed on the opposite side of said graphite ring from said metallicring, said sleeve having an inner conical surface adjacent said graphitering, said graphite ring having an outer sloping surface substantiallyparallel to said conical surface and spaced therefrom, and saidresilient O-ring being positioned between and sealingly engaging saidinner conical surface and said outer sloping surface.
 17. A sealingmeans according to claim 11 which includes a sleeve forming a part ofsaid fixed shaft assembly and disposed on the opposite side of saidGraphite ring from said metallic ring, said sleeve having an innercylindrical surface adjacent said graphite ring, said graphite ringhaving an outer cylindrical surface, and said resilient O-ring beingpositioned between and sealingly engaging said inner cylindrical surfaceand said outer cylindrical surface.
 18. A sealing means according toclaim 11 which includes a sleeve forming a part of said fixed shaftassembly and dispose on the opposite side of said graphite ring fromsaid metallic ring, said sleeve having an inner conical surface adjacentsaid graphite ring, said graphite ring having an outer cylindricalsurface, and said resilient O-ring being positioned between andsealingly engaging said inner conical surface and said outer cylindricalsurface.
 19. A sealing means according to claim 11 which includes asleeve forming a part of said fixed shaft assembly and disposed on theopposite side of said graphite ring from said metallic ring, said sleevehaving an inner cylindrical surface adjacent said graphite ring, saidgraphite ring having an outer sloping surface radially spaced from saidcylindrical surface, and said resilient O-ring being positioned betweenand sealingly engaging said inner cylindrical surface and said outersloping surface.
 20. A sealing means according to claim 11 whichincludes a protective retainer shell ring on the graphite ring, andpositioning means engaging said shell ring and said fixed shaft assemblyand operable for restricting rotation of said protective retainer shellring and said graphite ring with respect to said fixed shaft assembly.21. A sealing means according to claim 20 in which said fixed shaftassembly comprises a recess and said positioning means includes a pinconnecting said recess and said protective retainer shell ring torestrict rotation of said protective retainer shell ring and saidgraphite ring with respect to said fixed shaft assembly.
 22. A sealingmeans according to claim 11 in which said fixed shaft assembly includesa sleeve on the opposite side of said graphite ring from said metallicring, said sleeve having an inner recessed partially circular seat, saidgraphite ring having an outer cylindrical surface, and said resilientO-ring being positioned between and sealingly engaging said innerrecessed partially circular seat and said outer cylindrical surface.